Quiz

1.Carbon Monoxide is a pollutant emitted from car exhausts.
Which of its properties makes it harmful to humans

A. It dissolves in rain water to form acid rain
B. It forms a stable compound with blood
C. It combines with oxygen in the lungs
D. It has a corrosive action on lung tissue

2.The following gases are present in car exhaust fumes
-carbon dioxide, carbon monoxide, nitrogen dioxide, watervapour, nitrogen

Which of these gases is also present in unpolluted air?

A. Nitrogen only
B. Nitrogen and water vapour only
C. Nitrogen, carbon dioxide and water vapour only
D. Nitrogen, carbon monoxide, carbon dioxide and water vapour only

3.Mehtane, sulfur dioxide and carbon dioxide are gases which affect the

atmosphere and the environment. In what ways do these gases affect the

environment

Methane Sulfur Dioxide Carbon Dioxide

A. Depletion of Acid Rain Global Warming
ozone layer
B. Global Warming Photochemical smog Acid Rain

C.Photochemical Global Warming Depletion of
smog ozone layer

D.Global Warming Acid Rain Global Warming

4. In which list are the major components of the atmosphere placed in order of
increasing abundance

A. Oxygen > Nitrogen > Noble Gas
B. Oxygen > Noble Gas > Nitrogen
C. Nitrogen > Oxygen > Noble Gas
D. Nitrogen > Noble Gas > Oxygen



3. Alloys are mixtures of metallic substances. Which of the following pairs
are matched INCORRECTLY?
A. Brass – copper and zinc
B. Steel – iron and copper
C. Bronze – copper, zinc, and others
D. Sterling silver – silver and copper


5. When methane, CH4, burns in excess oxygen, the products would be
A. CH4O2
B. CO + H2O
C. CO + CH2OH
D. CO2 + H2O


6. A student performed an experiment and a gas was produced. After the gas
was collected and tested with a burning splint, a loud popping noise was
heard. Which of the following gases was produced?

A. Hydrogen
B. Oxygen
C. Carbon dioxide
D. Chlorine


7. Which of the following gases is known to shield the earth from harmful
ultraviolet radiation?
A. CO2
B. CFCs
C. SO2
D. O3

8. Which compound is INCORRECTLY matched to the functional group that it
contains?
A. CH3COOH hydroxyl
B. CH3OH hydroxyl
C. CCl3COOH carboxylic acid
D. C6H5COOH carboxylic acid

9. Ozone is a type of

A. nitrogen
B. oxygen
C. carbon dioxide
D. water vapor

10. In the upper atmosphere, ozone absorbs potentially harmful __________

radiation from the Sun.

A. Cosmic
B. gamma
C. magnetic
D. ultraviolet

11. Which one of the following is the most abundant gas in the atmosphere?

A. oxygen
B. nitrogen
C. hydrogen
D. carbon dioxide

12. With increasing altitude, air pressure __________.

A. increases at an increasing rate
B. decreases at a constant rate
C. decreases at an increasing rate
D. increases at a constant rate

13. O2 and O3 molecules are
A. allotropes.
B. structural isomers.
C. isotopes.
D. geometrical isomers.

14. Chlorofluorocarbons rise to the stratosphere and
A. react directly with stratospheric ozone to destroy it.
B. after interacting with UV energy, become free radicals, which destroy
ozone.
C. become free radicals that react with oxygen to create ozone.
D. react with free radicals to remove carbon dioxide

15. The combustion process for an effective fossil fuel must have an
activation energy that is neither too high nor too low. Why is it
problematic if the combustion has a very low activation energy?

A. The fuel will evaporate too easily and be hard to transport and store.
B. The fuel will ignite too easily and be hazardous.
C. Upon combustion, fuels with low activation energies produce greenhouse
gases.
D. Upon combustion, fuels with low activation energies will not release
useful amounts of energy.

Bibliography

http://library.thinkquest.org/CR0215471/global_warming.htm
http://www.graymont.com/applications_flue_gas.shtml
http://en.wikipedia.org/wiki/Natural_gas
http://www.merriam-webster.com/dictionary/desulfurization
http://en.wikipedia.org/wiki/Flue-gas_desulfurization
http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/C/CarbonCycle.html
http://www.emc.maricopa.edu/faculty/farabee/biobk/biobookps.html
http://library.thinkquest.org/11226/why.htm
http://www.factmonster.com/ipka/A0775714.html/
http://www.physicalgeography.net/fundamentals/9r.html
http://en.wikipedia.org/wiki/Carbon_cycle
http://www.windows2universe.org/earth/Water/co2_cycle.html
http://www.martinmarietta.com/Products/FGD.asp
http://biology.clc.uc.edu/courses/bio104/photosyn.htm
http://www.ftexploring.com/photosyn/photosynth.html
http://en.wikipedia.org/wiki/Global_warming
http://globalwarming.com/

Global Warming

Greenhouse Gases

Carbon dioxide and water vapour play important roles in maintainin uniformity in the temperature on Earth's surface.

Greenhouse gases are emissions that rise into the atmosphere and trap the sun's energy, keeping heat from escaping. This produces a warming effect called the greenhouse effect.



Greenhouse Gases - Atmosphere and the Environment

Sunlight enters the Earth and the atmosphere traps some of the radiation, keeping the Earth warm. Some gases such as CH4 (methane) and N2O (nitrous oxide) are very strong absorbers of radiation and are hence harmful to the earth but however,without these gases, Earth could be permanently covered with ice. The combustion of fossil fuels and large scale deforestation are causing a drastic increase in the production of greenhouse gases hence more carbon dioxide will rise into the atmosphere, trapping heat and causing an increase in the average temperature of the Earth. This phenomenon is hence known as Global Warming.

Solutions to pollution

Possible solutions to pollution

The most common pollutants are Carbon Monoxide and Oxides of Nitrogen. As such, the catalytic converter was invented to help solve this pollution problems

Uses of the Catalytic Converter

Catalytic converters contain platinum and rhodium as catalysts to oxidise carbon monoxide to carbon dioxide


2CO + O2 --> 2CO2

Oxides of nitrogen will be reduced to nitrogen gas

2NO + 2CO --> N2 + 2CO2


The products of the above reactions, carbon dioxide, nitrogen, water are not toxic hence catalytic converters are a very efficient in helping to clear up pollution emitted by cars.



Alternate ways of solving pollution problems

The alternate way of solving pollution problems is by burning natural gas instead of coals as coals contain sulfur which is a pollutant. Power stations in singapore are now burning more natural gas. Natural gas is mainly methane and contains no sulfur, which is less harmful.



Flue Gas Desulfurisation

The definition of flue gas desulfurisation is the reducing of sulfur dioxide emissions in power stations

Powdered limestone (calcium carbonate) is added to hot gases produced from the combustion of fuels such as coals at power stations. The heat will then decompose the limestone to give calcium oxide. An aqueous suspension of calcium oxide will react with the sulfur dioxide to form solid calcium sulfite. Calcium sulfite will then be oxidised by oxygen in the air to form calcium sulfate which is non-polluting. This process effectively decreases the production of sulfur dioxide. The formula for the process is as follows:


Calcium carbonate will react with sulfur dioxide to form solid calcium sulfite and carbon dioxide

CaCO3 + SO2 --> CaSO3 + CO2

Calcium Oxide reacts with sulfur dioxide to form calcium sulfite
CaO + SO2 --> CaSO3


Calcium sulfite is then oxidised by oxygen in air to form calcium sulfate.


2CaSO3 + O2 --> 2CaSO4

The Carbon Cycle

Here is a short clip for the introduction to the carbon cycle so sit back and relax!:D






The definition of the carbon cycle

The Carbon Cycle is the circulation of carbon atoms between living organisms and their surroundings. Carbon dioxide from the atmosphere is synthesized by plants into plant tissue, which is ingested and metabolized by animals and converted to carbon dioxide again during respiration and decay




Usage of Carbon Dioxide

Photosynthesis

In the presence of sunlight, Green Plants convert carbon dioxide and water to form glucose and oxygen.
6CO2 + 6H2O -->C6O12O6 + 6O2


Release of Carbon Dioxide

- Combustion

Burning of carbon containing fuel formed carbon dioxide and water.


C + O2 --> CO2
CH4 + O2 --> CO2 + 2H2O


- Respiration

C6O12O6 + 6O2 --> 6CO2 + 6H2O



Photosynthesis
Through the process of photosynthesis, plants remove carbon dioxide from the atmosphere and through this process green plants convert carbon dioxide and water into glucose and oxygen in the presence of sunlight.

6CO2 (g)+ 6H2O (l) --> C6H12O6 (aq) + 6O2 (g)

Our Ozone Layer

For starters, here is the definition of the ozone layer:

The Ozone layer is a layer of the Earth's atmosphere containing large amounts of ozone.


Ozone is an allotrope of oxygen and is a pale blue, almost colourless gas. It is non-toxic and small concentrations, but in concentrations of an estimated 100 parts per million, it will bring about many consequences and can prove to be especially dangerous for people with asthma.

The ozone layer is very important since it protects life on Earth from harmful ultraviolet light emitted from the sun. Without the ozone layer, we will suffer from various skin cancers, eye damage and may even bring about genetic disorder.



The Cause of the Depletion of the Ozone Layer

It has been discovered that by scientists that the ozone layer is being depleted by chlorofluorocarbons, compounds made up of carbon, chlorine and fluorine. These compounds, are widely use for propellents for aerosols and coolants in refrigerators etc.


How does CFC deplete the ozone layer?


When aerosol can is used or polystyrene packaging is burnt, CFC molecules escape into the air. These CFC molecules will then undergo homolytic fission in the presence of sunlight to produce chlorine atoms at the stratosphere.Chlorine atoms react with ozone molecules and convert them into oxygen molecules, thus destroying the ozone molecules.

Here is the equation involving the depletion of the ozone layer by chlorine atoms:
Cl + O3 --> ClO + O2
O + ClO --> Cl + O2

Effects of Pollutants

Carbon Monoxide

Carbon monoxide are harmful to use as our haemoglobin reacts better with Carbon Monoxide than Oxygen hence the Carbon Monoxide will react with the haemoglobin to form carboxyhaemoglobin. This will eventually cause the cells to die due to lack of oxygen


Particulates

Particulates such as dust and lead will cause harm to our human body as well.

Dust - Contributes to the formation of photochemical smog and cause breathing difficulties.
Lead - Causes lead poisoning and eventually causing permanent brain damage


Sulfur Dioxide

1. SO2 dissolves readily in rain water to form sulfurous acid, which can be oxidised by air to form sulfuric acid, forming Acid Rain.

SO2 + H2O --> H2SO3

2. Irritates eyes and attacks lungs, causing breathing difficulties.
Ozone
Leads To Formation of Photochemical Smog.
O2 and NO2 react in the presence of sunlight to form Ozone.
Ozone being highly reactive will react with unburnt Hydrocarbons and oxides of nitrogen to form peroxyacyl nitrates (PAN) which are lacrimators and cause tearing of eyes.


Oxides of Nitrogen
1. NO2 dissolve in rain water to form Acid Rain.

4NO2 + 2H2O + O2 --> 4HNO3


Effects of Acid Rain:

- Corrode metal structures/limestone buildings
- Lowers pH of water, kills aquatic life.

2. Irritates eyes and infects our lungs, causing breathing difficulties.